Engine Wear and UOAs

[buster]

Something to remember in all of this:

quote:

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Federal Mogul Corporation, a manufacturer of engine bearings, pistons, connecting rods and other engine parts, studied over 7,000 case histories of bearing distress and engine failure and never found engine oil to be the cause of a failure. Dirt, the number one cause of engine failure, was found to be responsible for 43.4% of failures, and insufficient lubrication, the second most common cause of failure, was responsible for 16.6% of failures. Insufficient lubrication is the general term used when not enough oil gets through to the engine to lubricate it (lack of oil volume).

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[1sttruck]

Looking closer at the 'normalized' iron rates posted above,

sample iron
3000 8.3
4000 6.6
3731 2.1
7762 3.8

since the 7762 mile rate includes the 3731 mile rate the rates should be the same, but it's obvious that 3.8 does not equal 2.1. In order to produce a rate increase at 7762 miles the rate for the next 4031 miles has to be greater than 3.8, and I get 5.4. So we see even with a bypass filter the assumed wear rate estimated from the iron levels has increased about 2.5x, from a 3.7k interval to a 7.7 interval. It might be reasonable level, but it has still increased with the longer oil change interval, and the level that we're estimating is optimistic as we don't have the filter debris and other films to add to the rate.

 

[1sttruck]

Using the data below I get a 'normalized iron wear rate' (normalized for sump and added oil, displacement, miles on oil) of:

14.3kmi 5.8
21.5kmi 6.0
7.2kmi 6.3 (rate for the second interval).

Again, no filter debris so the rates are optimistic, but we can compare using Amsoil bypass filters on this F150 and the Pontiac Grand Prix above. Running to 14k miles with a bypass filter is almost like using a K&N with no bypass out to 4k miles.


http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=002289

First number is at 14,326 (4/21/04), and second number is at 21,500 (11/17/04)

Iron 56 / 63

Oil is 8 quarts Amsoil S2K 0w-30

01 Ford F-150 SuperCrew 5.4

Yes, I just remembered today that I topped off shortly before I took the sample. Otherwise I would have mentioned that in my post. I changed both filters at 14k, and two more quarts of fresh meat. I suppose that just goes to show how good the oil would have been had I just changed another filter and poured in another fresh quart.